Late preterm infants (34-37 weeks gestation) account for the fastest growing, largest cohort of preterm births in the U.S. Despite comparable outward appearances, late preterm infants lack the developmental maturity of their term counterparts, predisposing them to unique, often unrecognized medical vulnerabilities and a concomitant high incidence of morbidity. One striking paradox emergent from these data is that late preterm infants who are breastfed tend to present with diagnoses of failure to thrive, jaundice, and dehydration at much higher rates than those who are not breastfed, a finding largely attributed to insufficient breast milk intake. Consequently, it is difficult to recommend breastfeeding as the optimal method of feeding and encourage its more widespread uptake among the late preterm population, despite the many, irrefutable long- and short-term health benefits that breastfeeding provides, particularly for infants born prematurely. While late preterm breastfeeding complications are often traced to infant-related issues, breastfeeding is a complex, reciprocal activity involving both infant and mother. It has become crucial, therefore, to understand the processes leading to both breastfeeding success and breastfeeding failure stemming from insufficient breast milk intake within the late preterm population. Accordingly, the primary aim of this qualitative, grounded theory study is to describe and explain the process of breastfeeding initiation and continuation among late preterm mother-infant dyads. Secondary aims are, 1) to place breastfeeding within the broader context of mothering a late preterm infant;and 2) to identify factors influencing the late preterm mother's decision to initiate and continue breastfeeding. Based mainly on the grounded theory techniques proposed by Strauss &Corbin, the study will utilize serial postpartum semi-structured interviews, observational field-notes, and secondary data collection methods (e.g., self-audio recordings, video review/reflection) for an estimated 10-18 mothers of late preterm infants in the development of a substantive theory. Theoretical sampling, memoing, and systematic coding utilizing the constant comparative method will be employed. This proposal satisfies two NINR objectives: 1) to identify and ameliorate the long-term consequences of prematurity, including complications of near-term infants;and 2) identify influences on decision-making that result in behavioral changes that promote health and prevent disease and disability. Results from this study are expected to provide a foundation for future research efforts seeking to narrow or eliminate breastfeeding health disparities for the late preterm populace. Additionally, this study will contribute to the currently underdeveloped knowledgebase surrounding late prematurity in general, and breastfeeding within this group, in particular.